Kiln for regeneration of contact material



5 Sheets-Sheet 1 SAROMETRIC CONDENSER FROM ELUTRIATOR INVENTOR ATTORNEYPansy CATALYST DRAG STREAM TO ELUTRIATOR E. V. BERGSTROM HOT i CATALYSTKILN FOR REGENERATION OF CONTACT MATERIAL Original Filed Aug. 15, 1956May 10, 1960 STACK" WATER sPRA LINE BURNER WATER s? Y y 1960 ZE. v.BERGSTROM 2,936,221

KILN FOR REGENERATION OF CONTACT MATERIAL Original Filed Aug. 15, 1956 5Sheets-Sheet 2 ATTORN Y May 10, 1960 E. v. BERGSTROM KILN FORREGENERATION 0F CONTACT MATERIAL 5 Sheets-Sheet 3 Original Filed Aug.15. 1956 I INVENTOR Em BY 1? ATTQRN May 10, 1960 E. v. BERGSTROM KILNFOR REGENERATION OF CONTACT MATERIAL Original Filed Aug. 15, 1956 5Sheets-Sheet 4 INVENTOR E B ATTORN E. V. BERGSTROM KILN FOR REGENERATIONOF CONTACT MATERIAL May 10, 1960 5 Sheets-Sheet 5 Original Filed Aug.15, 1956 NV NTOR 1 31567. I E m AT'TORN conditions.

terial, such as corhart, mullite or even iron balls.

KILN FOR REGENERATION on CONTACT MATERIAL Eric V. Bergstrom, Byram,Conn., assignor to Socony Mobil Oil Company, Inc., a corporation of NewYork Original application August 15, 1956, Serial No. 604,146. Dividedand this application January 24, 1958, Serial No. 711,022

6 Claims. (Cl. 23-288) This application relates to the conversion offluid reactants in the presence of a sub-divided solid contact ma terialon which deleterious combustible deposits are formed. One phase of theapplication is particularly directed to the removal of the deposits in aburning chamber or zone.

One aspect of this invention has particular application in regeneratinga fouled contact mass material used in the continuous convertion ofrelatively high boiling hydrocarbons to produce lower boilinghydrocarbons in the gasoline boiling range. It is well known in thepetroleum art to convert hydrocarbons by bringing them into contact witha conversion catalyst at proper reaction In the moving bed process ofhydrocarbon conversion a granular contact mass material is gravitateddownwardly as a substantially compact column through a reaction zonewherein it is contacted with fluid hydrocarbons to produce convertedproducts and downwardly through a regeneration zone as a compactedcolumn wherein it is contacted with a combustion-supporting gas to burnoff carbonaceous deposits found on the surface of the contact materialduring the conversion. The material is withdrawn from the bottom of onecolumn and introduced onto the top of the other column, therebycompleting a closed, continuous circuit.

The solid particle-form material may be catalytic or non-catalytic. Itmay partake of the nature of Fullers earth, natural or treated clays, orvarioussynthetic associations, such as, for example, silica or silicawith additions of alumina or zirconia or chromia. Some processes utilizegranular particles of inert refractory m;-

Su ficient heat is stored in these materials so that when the materialsare contacted with hydrocarbons, suitably prepared for conversion, theheat is released to effectively convert the hydrocarbons.

Although this invention will be disclosed with particular reference tocatalytic cracking, other conversion processes are contemplated, such ashydrogenation, dehydrogenation, cyclization, polymerization andalkylation. For these processes the contact material may have a size ofabout 460 mesh Tyler Screen Analysis, and preferably, may have a size of4-20 mesh. Regular shapes, such as spheres or beads, pellets and discs,are preferred, but irregular shapes may be utilized.

In all these conversion processes, a carbonaceous deposit is formed onthe surface of the contact material which interferes with itsperformance as a catalyst and heat carrying medium. It is customary inthe art to remove these deposits by burning in the presence of acombustion-supporting gas, such as air. The extent of these deposits onthe catalyst depends upon many factors.

Among these are the nature of the charge stock, the.

reaction temperature and pressure, the space velocity and theeatalyst-to-oil ratio. The space velocity is normally expressed as thevolume of oil (at 60 F.) introduced into the reactor per hour per volumeof catalyst-occupied space in the reactor. The catalyst-tooil ratio is aratio United States Patent M 2,936,221 Patented May 10, 1960 of thevolume ofcatalyst introduced into the reactor per volume of oil (at 60F.) introduced into the reactor. Where all other variables are fixed,however, the longer the catalyst is retained in the reaction zone, thegreater will the deposit on the catalyst become. This coke laydown isusually described as the percent coke per pound of catalyst. Byincreasing the catalyst circulation rate, this value may be reduced. Or,to look at it another way, the percent coke may be controlled bycontrolling the catalyst circulation rate, and hence, limited thereby tosome predetermined value.

Prior kilns consisted of series of alternate burning zones where burningwas conducted in the absence of cooling and cooling zones where heat wasremoved by means of heat transfer tubes. The kilns were undesirablyhigh, partly because of this required arrangement. This was particularlytrue in the case of kilns where the cooling was done in the absence ofburning. The undesirable height of kilns prevented use of systems havingkiln and reactor in vertical series and also in the side by side unitsan undesirably long feed elevator was required. Another problem was thatgas leaving burning zones, particularly in the lower and hottest part ofthe kilns, contained carbon monoxide and oxygen in combustibleproportions and this burned with liberation of considerable amounts ofheat both under the gas outlet ducts and in the stack, causingconsiderable damage to the troughs and ducts. This was accentuated bythe fact that gas leaving at least some of the lower burning zones leftat locations where catalyst was very hot and there were no coolingcoils. t

It is seen, from the prior discussion, that these hydrocarbon conversionsystems required apparatus structures which are of high altitude, forexample, 200-300 feet. The system comprises heavy vessels and piping,and involves the conveyance therethrough of many tons of contactmaterial, for example, 50-400 tons per hour. The structure required forthe support of such a system is of necessity strong and durable andhence, exceedingly expensive. Furthermore, a great amount of windbracing is necessary for vessels and piping supported at suchelevations. It is seen desirable to reduce the height" of the system andvessels to a minimum, conistent with efficient economical operation.

The object of this invention is to provide an improved kiln of simplerand more economical construction than those now employed in commercialcatalytic cracking units.

Another object of this invention is to provide an improved apparatus forregenerating adsorbentsby burning which overcomes the above-mentioneddilficulties encountered by the prior art.

It is a further object of this invention to provide a simplified kilnfor regeneration of fouled granular con tact material in which thecontact material will not be heat damaged and afterburning will beprevented.

It is a further object of this invention to provide a simple apparatusfor controlling the temperature of catalyst passed through thesimplified kiln hereinafter disclosed with minimum interference in theoperation of the kiln and minimumum danger of damage to the kiln or itsinternals. 7

These and other objects of the invention will be made readily apparentby reference to the following detailed description of the illustratedapparatus and process which shows the invention.

Figure l is a schematic layout of a complete catalytic cracking systemincorporating the simplified kiln;

Figure 2 is a vertical view, partially in section, of the simplified,annular kiln;

Figure 3 is an enlarged view of a portion of the lower section of thekiln shown on Figure 2;

Figure 4 is a fragmentary view showing the gas withdrawal channels andtheir support means;

Figure 5 is an end view of the gas withdrawal channeis and relatedsupport means;

Figure 6 is a fragmentary cross-sectional view of the kiln, taken onplane 6-6 of Figure 4, illustrating the shape and arrangement of thechannels;

Figure 7 is a top sectional view of a vertical vessel showing amodification of the instant invention.

- The above-indicated sketches are highly diagrammatic form, intendedonly as illustrative of the invention, and are not intended to limit.the invention thereof.

. he preferred form this invention involves an apparatus wherein spent,combustible-bearing granular adsorbent is passed downwardly through aconfined regeneration -'zone as a substantially compact gravitatingcolumn, air is supplied into said column at an intermediate level alongits length and part of the air passes up through an upper portion of thecolumn and is withdrawn from above the column, the other part passesdownwardly through the column, being cooled in the lower portion of thecolumn, and is withdrawn to sheltered regions at a low point in thecolumn where the hot gases are commingled with a coolant fluid and thecooled mixture is continuously withdrawn therefrom.

Referring to Figure .1, a complete unitary moving bed 'syste'm for thecatalytic conversion of hydrocarbons is shown. This system, hereinafterdescribed in detail to illustrate the invention, has a reactorthroughput of about 15,500 barrels per stream day. In such a system thecold catalyst storage vessel 10 may have a working capacity of 70 tonsof granular catalyst. The elevator 11 is used for filling the freshcatalyst storage vessel 10 and also for filling the system. It maysuitably be a conventional bucket-type elevator of about 15 tons perhour capacity.

:not be used in the lift. Air from the blower 117 is supplied throughthe line 118 to the lift tank 16 at a pressure of about 2 to 3 p.s.i. Apressure of about 1.5 p.s.i. is thereby maintained in the lift tank andserves to lift the catalyst up the lift leg 17. The air disengages fromthe catalyst in the disengager 18 and passes through the air outlet .119in the barometric condenser 290. The disengaged catalyst passesdownwardlythrough the elongated .feedleg 19 to the reactor 20, throughthe connecting conduits 21 from the reactor to the kiln 22 filling thesystem. The maximum rate of catalyst flow through the lift will be about5 to percent of maximum lift capacity or e of the order of 15 to 90 tonsper hour during filling and warming period.

Air from the blower 23 is passed through the line burner 24 and the kiln22 to heat the catalyst therein, the temperature of the air being about1000 F. After a period of three or four hours or so, catalyst at atemperature greater than 250 F., will reach the disengager 15, at

.which time circulation with air can be stopped and circulation withsteam under low vacuum conditions started.

This initial circulating rate can be rapidly increased to full capacityas soon as desired after the steam operation is begun. Full capacity inthe above desiribed system is about 365 tons of catalyst per hour. Mostof the catalyst flows down the elongated feed leg 19. A small stream iswithdrawn from the disengager 18 through the conduit 25 to serve as adrag stream to the elut-riator (not shown) to keep fines down in theunit. The disengager 18 is large enough to serve as a surge chamber aswell. as a disenthe outer Wall of the kiln.

4 gaging vessel. The barometric condenser 200, shown at the top ofFigure l, is connected to disengager 18 by the conduit 30. The steamemerges from the disengager 18 and flows to the barometric condenser.Cooling water is supplied to the barometric condenser 200 through theconduit 31 and the mixture flows down the tail pipe 32 to the hot-well33 from which the water overflows'to equipment not shown. Airmay beintroduced through valved conduit 29 into the barometric condenser incontrolled amounts to adjust the vacuum at the top of the lift to about6 pounds per square inch vacuum. Steam ejectors,

not shown, may be used to evacuate the air and non condensibles from thebarometric condenser.

The kiln 2-2 may be a vertical vessel of annular crosssection, having adiameter of about 24 feet and a height of about 40 feet. Referring toFigure 2, the kiln is seen to be adapted to handle a large mass ofcontact material. The kiln has a central aperture of circularcross-section of about .8 feet diameter, and the distance between theinner and outer wall is, therefore, about 8 feet. The beam span for thekiln internals is short. The vessel is readily adapted to operation atelevated pressures because of its inherently sturdy design. 7

Referring to Figure 2, the spent catalyst is introduced into the annularregion at the top of the kiln through a multiplicity of feed conduits21. For example, eight conduits can be used to feed contact material ateight :equally spaced locations around the top of the kiln. The

contact material is discharged from each conduit into a confining metalcone or pyramid 42 which is adapted .to confine the contact material,thereby preventing, the

separation'of the fine material into separate streams. Below the pyramid'42 is a plate 43 with pending pipes 44 passing therethrough. Detail 45represents a wedgeshaped header box which, with adjacent wedge-shapedboxes, forms an annular header in the annular kiln. The box terminatessubstantially short of the outer and inner walls of the kiln so as toleave area for gas from the bed below to pass up to outlet 48 above theheader box. The catalyst pipes 44 go right through the header box.Depending from the header boxes are a multiplicity of depending pipes 46adapted to lead gas from the boxes to a multiplicity of locationsuniformly distributed over the area of the kiln. One or more air inletducts 100 connect into the header boxes at spaced intervals aroundFunnel-shaped outlets 47 are attached 'to the bottom of'the dependingpipes :46

- to facilitate-the introduction of the gas into the gravitating bed.The purpose of the depending-pipe-air-introduction-scheme instead ofanother type of construction at the air inlet level, is to providemaximum free catalyst flow area downward and combustion air flow areaupward, particularly at the level of air entry into the catalyst bed.This construction also provide a minimum amount of metal projected 'intothe hottest part of the catalyst bed. Where channelvmembers are locatedat the hottest portion of the bed, damage has been experienced bybuckling of the member 'because of excessive temperature. The gasintroduction scheme described above :avoids this difliculty.

The combustiongas flows both upwardly and downwardly through the bed.The upwardly-directed stream is withdrawn through theconduit 48 fromthetop of the bed. Since the catalyst entering the bed at the top thereofis relatively cool, the fiue gas removed at the top being at the sametemperature as the catalystdoes not have the requisite temperature toproduce afterburning. Therefore, no cooling gas or dilution gas need beintroduced at the top of the bed to prevent afterburning. However, asnuffing steam connection has been provided at the top of the .kiln foremergency purposes.

A series of indirect heat exchanging coils Si is located in thelowersection of the bed to withdraw heat from the descending catalystand flue gas. Water, steam, liquid metals or salts' uch .as potassiumnitrate, can. be-used their support means are shown in more detail inFigures 3, 4, and 6. The channels are progrmsively wider from inner endto outer end, all being radially-directed in side by side relationship.They are blocked off on the outer ends and connected on the inner endsby bolted sup ports to the inner wall. The sleeves 70 enter through thewall under the channel and connect in the central core space of thevessel with a ring-type header 61 by means of feeding conduits 62. Theperforated pipe 63 is supported at its inner end in an orifice in theinner wall and is supported at its outer end by the brace 71. Below thegas collectors 51 is located a horizontally disposed plate 52. Amultiplicity of downwardlydirected pipes 54 feed the contact materialfrom the bottom of the bed in confined streams to an outlet cone 55. Theplate 52 and pipes 54 define a plenum chamber 1 53 in the bottom of thekiln. The pipes 54 feed contact :material from equally distributedlocations across the bottom of the bed, effecting withdrawal from alllocations across the bed at substantially equal rates of flow, andpermitting a confining of the outlet stream without ;avalanching orcascading of the catalyst. -;.streams are withdrawn from the bottom ofthe kiln through eight equally distributed conduits 56 into a lift tank16 located therebelow (as shown on Figure 2). The gas is removed fromthe enclosed region under the The confined ggas channels 51 through thedownwardly-directed pipes :58 into the plenum chamber 53. As shown onFigures "4, 5 and 6, the pipes 53 have ears 72 on the upper ends:adapted to support the outer ends of the channels 51.

"The enlarged lugs 73 on the pipes 53 are bolted together,

connecting adjacent pairs of pipes 58, thereby adding strength to thestructure. Catalyst carried over with the gas through the pipes 58 isseparated in the plenum chamber 53 and returned to the catalyst outletstream through the cones 55. Particle-free gas is withdrawn through theoutlet conduit 66 to a flue gas stack.

The blower 59 (Figure 2) is used to supply a large mass of cold airthrough the conduit 60 to a ring header 61. The header is connected byfeeding conduits 62 to a multiplicity of sleeves 70 (see Figure 4),which in turn connect with perforated pipes 63 horizontally located, oneunder each gas collector or channel. For example, a 12,000 c.f.m. fancan be used to supply this air to the collectors at about 8 inches ofwater differential. This cold air mixes rapidly with the hot flue gaswithdrawn from the bed, cooling it substantially, thereby eitherlimiting the maximum temperature under the channels below maximum safelimits when afterburning occurs or in many instances, completelyeliminating afterburning at this location. This cool air can also beused to provide 1 a suitable means of controlling the outlet catalysttemthe kiln to provide satisfactory heat balance in the systent. Sincedifiiculties arise when indirect cooling coils are placed back inservice after being out of operation,

the system of temperature adjustment is exceedingly use ful inpreventing cooling coil failures. The cooling coils are kept inoperation continuously and temperature adjustment of the catalyst isobtained by control of the temperature and/ or flow rate of the airintroduced under the channels. This prevents the cooling coils fromchanging in temperature any substantial amount and prevents the damagingstresses from being set up in the metal of the coils.

Referring to Figure 3, an enlarged fragmentary view shows in greaterdetail the cooling coils and the gas disengaging apparatus. The baflle64 is adapted to prevent spreading of the catalyst discharged from theconduits 54 into the cone 55. There is an annular space between the cone55 and baffle 64, the lower ends of the pipes 54 being supported by theupper edge of the battle and cone. Catalyst separated from the flue gasin the plenum chamber 53 returns to the catalyst stream through thespaces between the pipes 54. The valve 65 in the outlet conduit 66 maybe operated in conjunction with the valve 67 in the upper outlet conduit48 to balance the flow of gas in the upwardly and downwardly flowingstreams to provide efiicient regeneration of the contact mass materialthroughout the entirebed.

The kiln construction above illustrated provides for the gravitation ofa large mass of catalyst through a simplified, low altitude vessel, theannular cross-sectional area being substantially larger than thecross-section of previously used multi-zone kilns. In the exampleillustrated, the diameter may be 24 feet with a core diameter of 8 feet,providing an annular flow area 8 feet wide and of approximately 400square feet as compared with say a 12-foot square multi-zone kiln ofabout l44 square feet cross-section. The annular kiln has a beam span of8 feet providing for simple, rugged mounting of the kiln internals,thereby making the construction economical. In the system illustratedherein, the kiln height was 40 feet whereas an equivalent multi-zonekiln would be 110 feet high or thereabouts. It is seen that there is aconsiderable saving in height. This is exceedingly important in, thesesystems because less structural steel and supporting members can be usedif the vessels can be made shorter with a consequent economy inconstruction.

By operating at high enough catalyst circulation rates, the coke laydownmay be sufficiently limited to prevent heat damage to the catalyst inthe simplified kiln. The natural or treated clays can withstandtemperatures of about 1150 F. without serious damage, while the syn-\thetic catalyst, such as silica, may withstand higher temperatures ofthe order of 1250 F. In order to prevent exceeding these temperaturelimits, the circulation rate is maintained high enough to prevent thecoke laydown from exceeding about 1.0 percent for the syntheticmaterials and about 0.75 percent for the natural or treated c ays.

As an illustration of the invention, the above described moving bedsystem, using silica beads with chromia added of about A; inch diameter,and the following operating conditions:

Reactor throughput, barrels per stream day 15,500 Catalyst circulation,tons per hour 350 Oil inlet temperature, F.:

Vapor (80 percent of charge) 820 Liquid (20 percent of charge) 700Catalyst inlet temperature to reactor 1,070 Space velocity, volumes ofcharge at 60 F. per

hour per volume of catalyst-occupied reactor 7 space 1:1 Catalyst-to-oilratio, volumes per volume (at has a coke burning load of about 7500pounds per hour, when using a wide-cut, gas oil representing 47.5 to92.5 percent volume of Kansas crude. The temperature in the simplifiedkiln does not exceed a of 1250 F,

through the cooling zone.

"Patent Number 2,458,498.)

' top of the vessel. Hence, the carbon monoxide and oxygen gases staybechannels may range from about 9/ 1 to about 1/ 1.

introduced into the midpoint or the bed at a temperature of about 70 to100 F., one stream being withdrawn from the top at about 875 F., and theother stream being withdrawn from the bottom at about 1000" F. The hotcatalyst and line gas is cooled in the lower part of the kiln justbefore it reaches the outlet channels by passing This is the gas whichwould be expected to contain a combustible carbon monoxide and oxygenmixture, therefore,'by cooling at this point,

the amount of carbon monoxide in the gas reaching the channels isreduced. The dilution gas introduced under the channels may be cold air,flue gas, etc., and in some cases, steam. The amount of cold gasintroduced under the channels is enough so that if all the CO burned,the maximum gas temperature would not exceed about 1150 F. preferably,and 1250 F. in any case. In some cases this may prevent all or part ofthe carbon monoxide from burning, in which event the outlet gas mixturemay leave the kiln as low as 600-800 F. The cooling gas usually enterswithin 50 F., of atmospheric temperature, but higher temperatures 'maybe used, in which event more gas is required. It is also contemplated,within the broad scope of the invention, that just enough gas can beadded to change the carbon monoxide proportions out of thecombustible'range, but it is preferred to control the afterburning bythe dilution technique. By getting the cooling gas into contact with theflue gas as it leaves the catalyst,

the afterburning is controlled before it gets materially Started,thereby preventing destruction of not only the gas outlet ducts, but"also the gas collectors. If the exhaust gases were drawn directly fromthe channels, the total volume would be so great that a large amount ofcatalyst would be entrained in the withdrawn gas. However, by using aplenum chamber to separate this entrained catalyst and keep it in thevessel, the catalyst entrainment is maintained low. (Disclosed andclaimed in copending application for United States patent, Serial Number694,334, filedon August 31, 1946. now issued As previously indicated,about-one-half of the total flue gas is withdrawn from the The catalystis cool in that region.

low the temperature range in which afterburning occurs, and no cooling:coils are needed at the top of the vessel. 'The afterburning problemis, therefore, avoided in that region.

In operation, a. substantial portion of the heat released the kiln isremoved by the internal cooling coils 50.

For example, the amount of heat removed may range from about 30 percentto-about 55 percent. In general,

the'proportion of flue gas to cold air mixed under the The maximumcatalyst temperature in the kiln may range from about 1100 F. to about1250 F., and the temperature ofthe catalyst at the lower channel levelmay range from about 950 F. to about 1100 F. The deposits-onthe catalystentering the kiln may safely range from about 0.6 percent of thecatalyst weight to about 1.35 percent, and the range of coke depositswhich can safely be removed in the'kiln, may vary from about 0.5 percentof the catalyst weight to about 1.25 percent.

Some of the heatis removed with the flue gas, the total varying-fromabout percent to about 35 percent.

In some aspects, the invention is not restricted to the annular shape ofthekiln, particularly with relation to the method for preventingafterburning. It is also, not limited to the method of introducing-theburning air, as here shown andthe shape 'of the gas channels and thebelow the kilns. The confining ceiling 82 prevents the segregation ofcatalyst fines at the top of the column of catalyst in the vessel. Theheader box *83 is supported, horizontally, on brackets 84, 85, which areattached to the walls of the vessel 80. The header box covers less areathan the cross-section of the vessel 80, providing space for the upwardflow of gas around the box. Combustion-supporting gas is introduced intothe header box through the conduit 86, and the gas is distributedthrough the depending conduits 87 to a level substantially below thelocation of the header box.- .The gas flows, at least partially, upwardfrom the depending conduit outlets, through the bed of contact material,to the top of the vessel, above the level of the contact column; The gasis then withdrawn from the vessel through the conduit '88.

This application is a division of application, Serial Number 604,146,filed August 15, 1956.

I claim:

1. A kiln adapted for regeneration of a solid particle form contact massmaterial which has become spent by deposition of a carbonaceous depositthereon and which exists at a temperature suitable for initiatingcombustion of said deposit, which comprises in combination: ayertioalvessel, means for introducing spent contact mass material into the topof the vessel, said contact'material gravitating downwardly through thevessel as a substantially compact column, means for introducingconcomitantly a first and second stream of combustion-supporting gasinto the column at an intermediate level along the length of the vesselspaced below said contact material inlet means, means for withdrawingthe first stream of flue gas from an upper section of the vessel withoutcooling the gas during passage through the column, indirect heatexchanger coils located in the lower section of the vessel below the gasinlet means adapted to contact and cool the gravitating contact mass andthe second stream of combustion-supporting gas passing downwardlythrough the column, a group of gas collectors located below the coolingcoils adapted to provide a gas collecting space shielded from thecontact material column, means for introducing a cooling gas insufiicient amount directly into the gas collectors to commingle with thehot flue gas in the ratio of between to 1 and 1' to 1 to preventafterburning, a horizontally located-partition plate near the bottom ofthe vessel and below the collectors defining an enclosed plenum regionin the bottom of the vessel, conduit means for withdrawing the mixtureof flue gas and cooling gas with a minor proportion of particles fromthe collectors into the enclosed plenum region, a multiplicity ofconduits depending from said partition plate adapted for the withdrawalof particleform material from the bottom of the column to locations nearthe bottom of the vessel, means defining outlets located below theoutlets'of the depending conduits in the bottom of the vessel throughwhich particle-form material discharged from the conduits is separatedfrom the gases in the enclosed plenum region and is withdrawn, and meansdefining an outlet at an upper level of the enclosed plenum regionlocated below the partition plate and above the outlets of the dependingconduits through which denuded gases are withdrawn.

2. In a kiln of annular cross-section adapted for regeneration of agravitating substantially compact columnofsolid particle-form contactmassmaterial whichhas become spent by deposition of a carbonaceousdeposit thereon and which is regenerated by passing acombustion-supporting gas through the column, apparatus for separatelyremoving particle-form material and flue gas from the bottom of thevessel, comprising in combination: a multiplicity of elongated gascollectors radially disposed and substantially equally distributedacross the cross-section of the vessel within the lower section thereof,said collectors being supported by bracketed connection to the innerwall of the vessel, said collectors shaped in the form of invertedchannels with the inner and outer ends of the channels closed and thechannels being progressively wider from the inner end to the outer end,a horizontally disposed partition plate located below the collectorsadapted to form an enclosed annular plenum region in the bottom of thevessel, vertically disposed gas transfer pipes attached to the top ofsaid partition plate beneath each collector at locations near the outerend of the collectors, said transfer pipes having ears at the upper endsadapted to contact the edge of the collector to provide supporttherefor, a multiplicity of radially disposed perforated pipes havingcapacity for introduction of a large volume of gas into the collectorsand located beneath the collectors, means for introducing a cooling gasfrom the central region of the annular kiln into the perforated pipes,means defining outlets for solid contact material in the bottom of thevessel, a multiplicity of withdrawal conduits depending from saidpartition plate and terminating at said means defining outlets, saidmeans defining outlets adapted to permit withdrawal of solid contactmaterial from both said multiplicity of conduits and from the enclosedannular plenum region, and, means for withdrawing denuded gas locatedbelow the partition plate and substantially above the bottom of thevessel.

3. A kiln for the regeneration of a spent granular contact material,said regeneration being performed by burning carbonaceous deposits fromthe surface of the contact material, which comprises in combination: avertical vessel of substantially uniform annular horizontalcross-section, a multiplicity of feeding conduits substantially equallydistributed about the top of the vessel adapted for the gravitation ofcontact material into the vessel, a multiplicity of wedge-shaped headerboxes coated near the top of the vessel horizontally disposed to coveran annular area less than the cross-sectional area of the vessel, saidboxes being supported by brackets attached to the inner and outer wallof the vessel at a spaced distance therefrom, downwardly-directedconduits passing through said header boxes adapted to transfer contactmaterial therethrough to the top of a gravitating substantially compactcolumn below, a multiplicity of depending conduits attached to saidheader boxes adapted to introduce combustion-supporting gas from saidboxes into the column of contact material at locations substantiallyequally distributed across the column and at a level near the midpointof the vertical length of the vessel, conduits attached to said headerboxes for introducing combustion-supporting gas, at least one conduitattached to said vessel near the top for the withdrawal of flue gas at alocation above the top of the column, at least one layer of horizontallydisposed heat transfer tubes substantially equally distributed acrossthe annular crosssection of the vessel in the lower portion of thevessel, a multiplicity of radially disposed gas collector channelslocated just below the cooling coils and substantially equallydistributed across the annular area, the collectors being invertedchannels with walls'at both ends and having a uniformly increasing widthfrom the inner end to the outer end, the collectors being partiallysupported by brackets attached to the inner ends which are attached tothe inner wall of the vessel, a horizontally disposed annular partitionplate located below the collectors defining an enclosed chamber in thebottom of the vessel,

substantially vertical gas transfer pipes attached to the 10 upper sideof said partition plate under the collectoisi at locations near theouter end of the collectors adapted to withdraw gas and minor amounts ofentrained contact material from beneath the collectors into the lowerenclosed chamber, said pipes having ears at the upper end adapted tocontact the edges of the collectors providing partial support thereforand having brackets along the length which are interconnected to provideadditional rigidity to the structure, radially-directed perforated pipeslocated under the gas collectors, means for introducing a cooling gasinto said pipes through the inner wall of the vessel to mix with theflue gas under' the channels, funnel-shaped outlet cones substantiallyequally distributed about the bottom of the vessel, com-- cal baflleslocated within said funnel-shaped outlet cones,- defining a withdrawalspace between the battle and cone, a multiplicity of depending conduitsattached to the bot-- tom of said partition plate and connected at thelower end between the upper edges of the bafile and cone, the: conduitsand outlet cones so arranged to provide sub stantially uniformwithdrawal across the bottom of the: column of contact material, atleast one outlet conduit connected through the wall of the vessel belowthe partition plate at a location above the outlet cones and amultiplicity of widthdrawal conduits attached to the outlet cones forwithdrawal of streams of contact material therefrom.

4. A kiln adapted for regeneration of a solid particleform contact massmaterial which has become spent by deposition of a carbonaceous depositthereon, which comprises in combination: a vertical vessel, means forintroducing spent contact material into the top of the vessel, means forremoving regenerated contact material from the bottom of the vessel ahorizontally dis posed combustion-supporting gas header box located inthe upper section of said vessel, brackets attached to the walls of thevessel adapted to support the header box, said header box covering lessthan the total cross-sectional area of the vessel, vertical conduitsthrough the header box adapted to transfer contact materialtherethrough, conduit means adapted to introduce a combustion-supportinggas into the header box, depending conduits from the bottom of saidheader box adapted to introduce cornbustion-supporting gas into thevessel at a multiplicity of locations across the vessel and at a levelsubstantially below the vertical conduits, and a discharge conduitattached to the upper portion of the vessel above the level of contactmaterial in the vessel adapted for withdrawal of at least a portion ofthe combustion gases formed in the vessel.

5. A kiln for the regeneration of a spent granular contact materialcomprising: an upright vessel adapted for the gravitation of a compactmass of granular contact material therethrough, at least one gas headerbox located within the vessel and near the upper end thereof, saidheader box covering less than the cross-sectional area of the vessel,whereby the free upward transfer of gas is permitted between the headerbox and the walls of the vessel, at least one conduit adapted to feedcontact material onto the upper surface of each header box, said conduitbeing projected through the top of said vessel, vertical transfer pipeslocated through the header box for the transfer of granular contactmaterial through the header box to form the upper end of a gravitatingcontinuous column of contact material below the header box, dependingelongated conduits attached to said header box and communicatingtherewith, said depending conduits being terminated at a uniformelevation substan--.

tially below the surface of the gravitating continuous collumn, at leastone gas introduction conduit projected laterally through the vessel andcommunicating with said header box, whereby air is fed to the header boxand discharged from the depending conduits into the gravitating 1 columnat an intermediatae level, a first gas outlet conduit means located nearthe top of the vessel and above A,

, 11 the, header box, a second gas outlet conduit means. located nearthe bottom of the vessel, and at least one conduit attached to thebottom of said vessel for withdrawal of contact material fromv saidvessel.

6. A kiln for the regeneration of a spent granular contact materialtin amoving bed hydrocarbon Conversion system comprising: an upright vesseladapted for gravitation of, a compact mass of granular contact materialtherethrough, a series of gas header boxes located at a uniform levelwithin the vessel near the upper end thereof, said header boxes coveringless than the total cross-section of the vessel, whereby the free upwardtransfer of gas is permitted between the header boxes and between eachheader box and the wall of the vessel, a multiplicity of conduitsadapted to feed contact material to the upper surface of each headerbox, said conduits being projected through the top of said vessel, shortvertical transfer pipes located through the header boxes for thetransfer of granular contact material through the header boxes to formthe upper end of a gravitating continuous column of contact materialbelow the header boxes, depending elongated conduits attached to saidheader boxes and communicating therewith, said depending conduits beingterminated, at a uniform elevation substantially below the surface ofthe gravitating continuous column, gas introduction conduits projectedlaterally through the vessel and communicating with the header boxes,adapted to feed air to the header boxes for transfer through thedepending conduits to contact the gravitating column of contact materialsubstantially below the surfaceof the column, a firstseries ofgasoutletconduits attached near the upper end of thetvessel, adapted toWithdraw combustion gas from the vessel at a level above the headerboxes, indirect heat transfer conduits located in the vessel below thelower end of the elongated depending conduits, adapted for thewithdrawal of heat from the gravitating column of contact material,.amultiplicity of elongated gas collectors horizontally disposed. andsubstantially uniformly distributed across the cross-section of the 12vessel: at alevel below the heat transfer conduits, said collectorsshaped in the form of enclosed inverted channels, a horizontallydisposed partition plate located below the collectorsvadapted to form anenclosed plenum region in the bottom of the vessel, vertically disposedgas transfer pipes attached to the top of said partition plate beneatheachcollector, said pipes adapted to transfer gas and entrainedparticles of contact material from beneath the collectors to saidenclosed plenum region, a multiplicity of elongated perforated pipeshaving capacity for introduetion of alarge volume of gas into thecollectors and located beneath the collectors, means for introducing acooling gas into the perforated pipes at a substantial and variable flowrate, outlet conduits attached to the bottom of the vessel andcommunicating with the bottom of the enclosed plenum region forwithdrawal of contact material from said vessel, a multiplicity ofdepending conduits attached to said partition plate and terminated abovethe outlet conduits in the lower portion of the enclosed plenum region,adapted for the transfer of the bulk of the gravitating contact materialinto the outlets, a second series of gas outlet conduits projectedthrough the wall of the vessel and communicating with said enclosedplenum region, at a level substantially above the outlet conduits,whereby gas is removed from the enclosed plenum region free of contactmaterial and entrained contact material removed from the collectors withthe gas is dropped out of the gas in said enclosed plenum regions andreturned to the gravitating stream of contact material through theoutlet conduits at the bottom of said vessel.

References Cited in the file of this patent UNITED STATES PATENTS2,409,751 Gerhold Oct. 22, 1946 2,561,408 Peavy July 24, 1951 2,666,731Bergstrom Jan. 19, 1954 2,695,220 Bergstrom Nov. 23, 1954 2,716,091 RayAug. 23, 1955

1. A KILN ADAPTED FOR REGENERATION OF A SOLID PARTICLE FROM CONTACT MASS MATERIAL WHICH HAS BECOME SPENT BY DEPOSITION OF A CARBONACEOUS DEPOSIT THEREON AND WHICH EXISTS AT A TEMPERATURE SUITABLE FOR INITIATING COMBUSTION OF SAID DEPOSIT, WHICH COMPRISES IN COMBINATION: A VERTICAL VESSEL, MEANS FOR INTRODUCING SPENT CONTACT MATERIAL MATERIAL INTO THE TOP OF THE VESSEL, SAID CONTACT MATERIAL GRAVITATING DOWNWARDLY THROUGH FOR INTRODUCING CONCOMITIALLY COMPACT COLUMN, MEANS FOR INTRODUCING CONCOMITANTLY A FIRST AND SECOND STREAM OF COMBUSTION-SUPPORTING GAS INTO THE COLUMN AT AN INTERMEDIATE LEVEL ALONG THE LENGTH OF THE VESSEL SPACED BELOW SAID CONTACT MATERIAL INLET MEANS, MEANS FOR WITHDRAWING THE FIRST STREAM OF FLUE GAS FROM AN UPPER SECTION OF THE VESSEL WITHOUT COOLING THE GAS DURING PASSAGE THROUGH THE COLUMN, INDIRECT HEAT EXCHANGER COILS LOCATED IN THE LOWER SECTION OF THE VESSEL BELOW THE GAS INLET MEANS ADPATED TO CONTACT AND COOL THE GRAVITATING CONTACT MASS AND THE SECOND STREAM OF COMBUSTION-SUPPORTING GAS PASSING DOWNWARDLY THROUGH THE COLUMN, A GROUP OF GAS COLLECTORS LOCATED BELOW THE COOLING COILS ADAPTED TO PROVIDE A GAS COLLECTING SPACE SHIELDED FROM THE CONTACT MATERIAL COLUMN, MEANS FOR INTRODUCING A COOLING GAS IN SUFFICIENT AMOUNT DIRECTLY INTO THE GAS COLLECTORS TO COMMINGLE WITH THE HOT FLUE GAS IN THE RATIO OF BETWEEN 1/9 TO 1 AND 1 TO 1 TO PREVENT AFTERBURNING, A HORIZONTALLY LOCATED PARTITION PLATE NEAR THE BOTTOM OF THE VESSEL AND BELOW THE COLLECTORS DEFINING AN ENCLOSED PLENUM REGION IN THE BOTTOM OF THE VESSEL, CONDUIT MEANS FOR WITHDRAWING THE MIXTURE OF FLUE GAS AND COOLING WITH A MINOR PROPORTION OF ARTICLES FROM THE COLLECTORS INTO THE ENCLOSED PLENUM REGION, A MULTIPLICITY OF CONDUITS DEPENDING FROM SAID PARTITION PLATE ADAPTED FOR THE WITHDRAWAL OF PARTICLEFROM MATERIAL FROM THE BOTTOM OF THE COLUMN TO LOCATIONS NEAR THE BOTTOM OF THE VESSEL, MANS DEFINING OUTLETS LOCATED BELOW THE OUTLETS OF THE DEPENDING CONDUITS IN THE BOTTOM OF THE VESSEL THROUGH WHICH PARTICLE-FORM MATERIAL DISCHARGED FROM THE CONDUITS IS SEPARATED FROM THE GASES IN THE ENCLOSED PLENUM REGION AND IS WITHDRAWN, AND MEANS DEFINING AN OUTLET AT AN UPPER LEVEL OF THE ENCLOSED PLENUM REGION LOCATED BELOW THE PARTITION PLATE AND ABOVE THE OUTLETS OF THE DEPENDING CONDUITS THROUGH WHICH DENUDED GASES ARE WITHDRAWN. 